Credit: The Associated Press

Palestinians launch fireworks during celebrations in the West bank city of Ramallah, late Sunday, July 20, 2014. The Hamas' armed wing said it has captured an Israeli soldier during fighting in the Gaza Strip. Speaking on a Hamas television station, spokesman Abu Ubaida said "we have captured a Zionist soldier and the occupation has not admitted that." The claim could not immediately be verified and the Israeli military said it was investigating the report. (AP Photo/Nasser Nasser)

CAIRO — With high hopes but low expectations, the U.S. stepped up calls Monday for an international push to end fighting in the Gaza Strip as President Barack Obama sent his top envoy to the Mideast to help broker a new cease-fire between Israel and Hamas militants — the third since 2009.

Voicing fresh concern about civilian casualties, Obama reaffirmed his belief that Israel has the right to defend itself against a barrage of more than 1,500 rockets being launched by Hamas.